The overall objectives of our program are to obtain quantitative information in defined areas of the Central Nervous System (CNS) about normal metabolic processes and functions related to nitrogenous compounds; to correlate such information--whenever possible--with histological, physiological and behavioral parameters, and to compare the biochemical information obtained, with similar data obtained under different physiological or pharmacological conditions. Of primary interest to our research are amino acids with potential neurotransmitter properties. Since many of these compounds exist in the CNS at relatively high concentrations, our program is based upon the premise that these amino acids may have multiple functions in the nervous system. We are investigating: 1. The relationship between metabolism of nitrogenous and related compounds (specifically, amino acids) and osmoregulatory processes in the CNS of the toad Bufo boreas. 2. Amino acid metabolism in the CNS of the rat and chick, under different physiological and pharmacological conditions with attention focused upon the role of B6 vitamers and pyridoxal kinase and oxidase as regulatory agents. 3. The GABA shunt pathway in normal and regenerating nerves as well as in the ganglia of the cockroach (Periplaneta americana). 4. The metabolism of specific proteins in CNS tissues in vitro and the identification of regulatory steps that may be affected by neurotransmitters and related compounds.